Referring to FIG. 1, one example of a wide format ink jet printer 10 includes right and left side housings 72, 74, and is supported by a pair of legs 76. The right housing 72, shown in FIG. 1 with a display and keypad for operator input and control, encloses various electrical and mechanical components related to the operation of the printer 10. The left housing 74 encloses ink reservoirs 86 which feed ink to the ink-jet printheads 82 via plastic conduits 84, which run between each ink-jet printhead 82 and each ink reservoir 86. In some printer embodiments, no separate ink reservoirs 86 or tubing 84 is provided, and printing is performed with ink reservoirs integral to the printheads. Housing 72 or 74 may also include a maintenance station to clean and cap the printheads as needed. A printing region extends all or part of the way between the two housings 72 and 74.
Either a roll of continuous print media (not shown) is mounted to a roller on the rear of the printer 10 to enable a continuous supply of paper to be provided to the printer 10 or individual sheets of paper (not shown) are fed into the printer 10. In the case of roll-fed media, the media is cut after printing an image. A platen 78 forms a horizontal surface which supports the print media, and printing is performed by selective deposition of ink droplets onto the paper. During operation, a continuous supply of paper is guided from the roll of paper mounted to the rear of the printer 10 across the platen 78 by a plurality of rollers (not shown) which are spaced along the platen 78.
Print carriage 12 is supported above the platen 78 by primary guide rail 70. The print carriage 12 includes a plurality of ink-jet printheads 82 mounted therein. In the example shown in FIG. 1, four printheads 82 are mounted on the print carriage 12, although it is contemplated that any number ink-jet printheads 82 can be provided. A motor and a drive belt mechanism (not shown) are used to drive the print carriage 12 back and forth along the primary guide rail 70, as denoted by bidirectional arrow 80.
For high quality printing, it is sometimes necessary to monitor the characteristics of the printed image. For example, a spectrophotometer may be used to measure the colors being provided by the printed ink, relative to the intended colors. If it is found that the colors are outside the desired range, then adjustments may be made. Such adjustments may include cleaning of the printhead, adjusting the drop size ejected by the printhead, or adjusting the number of droplets ejected for providing a particular desired color, for example.
When permanently affixing an optical measurement device, such as a spectrophotometer to a printer carriage, the mass of the carriage is significantly increased when the device is mounted to it, thereby requiring more expensive rail and motor systems in the printer to compensate for the increased mass, particularly for high throughput printing requiring high velocity and acceleration of the printhead carriage. Also, for the case of an inkjet printing system, the optical measurement device is unable to make precise measurements when it is contaminated with ink mist and it can be difficult to shield the device adequately from the ink mist when it is mounted so closely to the source of the ink mist generation (e.g. when the optical device is mounted next to the printheads during printing).
Accordingly, there is a need in the art for an apparatus and method for selectively coupling a device, such as an optical measurement device, to a carriage, such as a printer carriage, as needed so that the optical measurement device does not spend its life span mounted to the carriage. In doing so, it may be necessary to move components of the printing system in a manner that gives the carriage a path to reach the optical measurement device even through there may be an intervening mechanism, such as an activation mechanism for a media cutting tool, in a path between the printing region of the carriage and the optical measurement device in its parked position.